Lucina as a character is a blank slate, and I don't like her very much. Her sole personality trait is her survivor angst because she's from an apocalyptic future, but that's a stereotype that I've seen on 2 different characters (Future Trunks and Silver the Hedgehog, there could be more), and she's mostly a glorified messenger, so her character is redundant to me. She's only popular because she's a pretty face, she's in Smash Bros., and her portrayal as "Marth" caught everyone off guard when Awakening was in it's baby steps. I'm new to this fanbase and all, but seeing fans foam at the mouth from the sheer sound of her name makes me angry.
I believe her popularity was an accident, and I despise her for such. But that's just me, I despise any character or game that's popular and hip for no reason.